During a teeth-cleaning operation, the usual final step is to polish the teeth with a rotating tool and a mild abrasive. Due to more stringent hygienic requirements, it is now common practice to utilize a disposable plastic tool head which contains a drive shaft and a rubber polishing element, both of which are rotatably mounted in an angled sleeve. The tool head is connected to a normally non-disposable hand-held unit for supporting and driving the tool head. The driving power unit is the same unit which is used to drive other tool heads of the nondisposable type and hence is a relatively durable, substantial unit capable of handling this variety of tool heads.
Most tooth cleaning operations are performed by a dental hygienist, and a majority of these are women who find the all-purpose power units uncomfortable to handle.
In view of the forgoing it is believed that a need exists for a power unit that is specifically designed for use with disposable tool head polishing units. A key component of that unit is a low cost but reliable coupling to the disposable tool head.
Some drive units, particularly those used in Europe, do not mate with the disposable polishing heads currently being used in the United States. Moreover, most tooth cleaning and polishing operations outside of the U.S. were being performed by dentists rather than dental hygienists. However, in recent years, this situation is changing so that more and more dental hygienists are performing those tasks. Thus, a need also exists for a coupling assembly that will fit a power unit and the disposable polishing head.